1. Technical Field
The present invention relates in general to an improved means for monitoring the physical condition of a data recording device, and in particular to an improved means for identifying damage to the components of a data recording device. Still more particularly, the present invention relates to an improved method for detecting fractures in a recording head or tape guide in a data tape drive.
2. Description of the Prior Art
Data recording devices, such as data tape drives, record information to or read information from media in a data storage device, such as the data tape of a tape cartridge. As shown in FIG. 1, data tape drives utilize one or more transducer heads 1 having air bleed grooves or slots 3 that define side walls 5. The air bleed slots 3 are provided for optimizing the performance of the transducer head 1. For example, U.S. Pat. No. 5,636,085 discloses a magnetic read/write assembly for a flexible disk drive having rails with air bleed slots that enable a low flying height for the media relative to the electromagnetic elements.
Referring again to FIG. 1, air bleed slots 3 are typically formed in the transducer head 1 in a direction that is perpendicular to the direction of travel of the tape (indicated by arrows 7). However, the slots also may be formed or cut in directions parallel to the direction of travel of the magnetic tape. The air bleed slots allow the tape to ride closer to the read and write elements in the head by bleeding off the boundary layer air which sticks to the moving tape. Although tape tension is used to wrap the tape over the head, high density recording requires the tape to hydrodynamically fly extremely close to the recording elements.
Transducer heads and the tape guides adjacent to them are typically formed from sensitive materials that are somewhat brittle in nature, and are subject to brittle fracture damage due to vibration, shock, and incidental contact with the media. When air bleed slots or other mechanical formations are formed in transducer heads and tape guides, areas of stress concentration occur and may increase the likelihood of damage to these components. The side walls of the transducer head are particularly vulnerable to stress concentrations and fractures. When a transducer head or tape guide is damaged, the media or data tape may be exposed to the sharp edges 9 (FIG. 1) of the fracture. Unless the situation is quickly remedied, extensive amounts of the media can be damaged or destroyed, and valuable information can be permanently lost. Thus, a method for detecting damage to the transducer head and tape guide of a data recording device is needed.
A data tape drive for recording information on the data tape of a tape cartridge has a transducer head with air bleed slots that define side walls, a tape guide, and a device for detecting damage to the transducer head and tape guide. The damage detection device has a conductor loop that is located along the outer edges of the air bleed slots and tape guide for detecting any brittle fracture damage that may be present. The conductor loop is a thin filament of wire that is preferably attached to the ends of the side walls. Alternatively, the filament is mounted along the side walls just below the top surface of the side walls to avoid contact with the moving data tape during operation of the data tape drive. When the transducer head or tape guide experiences a fracture, such as a fracture in one of the side walls, the delicate filament breaks and forms an open circuit. The open circuit in the conductor loop is detected by the data tape drive so that remedial actions can be taken. Without the damage detection device, large quantities of the data tape moving past the transducer head and/or tape guide would be scraped over or gouged by the fracture and permanently damaged, including loss of the information recorded on the data tape.